#include <QtWidgets>
#include "cell.h"
#include "spreadsheet.h"

Spreadsheet::Spreadsheet(QWidget *parent)
    : QTableWidget(parent)
{
    autoRecalc = true;

    setItemPrototype(new Cell);
    setSelectionMode(ContiguousSelection);

    setWindowTitle(tr("New Dow"));
    setAttribute(Qt::WA_DeleteOnClose);

    connect(this, SIGNAL(itemChanged(QTableWidgetItem*)), this, SLOT(somethingChanged()));

    clear();
}

void Spreadsheet::cut()
{
    copy();
    del();
}
void Spreadsheet::copy()
{
    QTableWidgetSelectionRange range = selectedRange();
    QString str;

    for (int i = 0; i < range.rowCount(); ++i) {
        if (i > 0)
            str += "\n";
        for (int j = 0; j < range.columnCount(); ++j) {
            if (j > 0)
                str += "\t";
            str += formula(range.topRow() + i, range.leftColumn() + j);
        }
    }
    QApplication::clipboard()->setText(str);
}
void Spreadsheet::paste()
{
    QTableWidgetSelectionRange range = selectedRange();
    QString str = QApplication::clipboard()->text();
    QStringList rows = str.split('\n');
    int numRows = rows.count();
    int numColumns = rows.first().count('\t') + 1;

    if (range.rowCount() * range.columnCount() != 1
            && (range.rowCount() != numRows
                || range.columnCount() != numColumns)) {
        QMessageBox::information(this, tr("Spreadsheet"),
                tr("The information cannot be pasted because the copy "
                   "and paste areas aren't the same size."));
        return;
    }

    for (int i = 0; i < numRows; ++i) {
        QStringList columns = rows[i].split('\t');
        for (int j = 0; j < numColumns; ++j) {
            int row = range.topRow() + i;
            int column = range.leftColumn() + j;
            if (row < RowCount && column < ColumnCount)
                setFormula(row, column, columns[j]);
        }
    }
    somethingChanged();
}
void Spreadsheet::del()
{
    QList<QTableWidgetItem *> items = selectedItems();
    if (!items.isEmpty()) {
        foreach (QTableWidgetItem *item, items)
            delete item;
        somethingChanged();
    }
}

void Spreadsheet::selectCurrenRow()
{
    selectRow(currentRow());
}
void Spreadsheet::selectCurrenColumn()
{
    selectColumn(currentColumn());
}
void Spreadsheet::recalculate()
{
    for(int row=0; row<RowCount; ++row)
    {
        for(int column=0; column<ColumnCount; ++column)
        {
            if (cell(row, column))
                cell(row, column)->setDirty();
        }
    }
    viewport()->update();
}
void Spreadsheet::setAutoRecalculate(bool recalc)
{
    autoRecalc = recalc;
    if (autoRecalc)
        recalculate();
}
void Spreadsheet::findNext(const QString &str, Qt::CaseSensitivity cs)
{
    int row = currentRow();
    int column = currentColumn() + 1;

    while (row < RowCount) {
        while (column < ColumnCount) {
            if (text(row, column).contains(str, cs)) {
                clearSelection();
                setCurrentCell(row, column);
                activateWindow();
                return;
            }
            ++column;
        }
        column = 0;
        ++row;
    }
    QApplication::beep();
}
void Spreadsheet::findPrevious(const QString &str, Qt::CaseSensitivity cs)
{
    int row = currentRow();
    int column = currentColumn() - 1;

    while (row >= 0) {
        while (column >= 0) {
            if (text(row, column).contains(str, cs)) {
                clearSelection();
                setCurrentCell(row, column);
                activateWindow();
                return;
            }
            --column;
        }
        column = ColumnCount - 1;
        --row;
    }
    QApplication::beep();
}
QString Spreadsheet::currentLocation() const
{
    return QChar('A' + currentColumn())+ QString::number(currentRow() + 1);
}
QString Spreadsheet::currentFormula() const
{
    return formula(currentRow(), currentColumn());
}
QTableWidgetSelectionRange Spreadsheet::selectedRange() const
{
    QList<QTableWidgetSelectionRange> ranges = selectedRanges();
    if (ranges.isEmpty())
        return QTableWidgetSelectionRange();

    return ranges.first();
}
void Spreadsheet::clear()
{
    setRowCount(0);
    setColumnCount(0);
    setRowCount(RowCount);
    setColumnCount(ColumnCount);

    for (int i = 0; i < ColumnCount; ++i) {
        QTableWidgetItem *item = new QTableWidgetItem;
        item->setText(QString(QChar('A' + i)));
        setHorizontalHeaderItem(i, item);
    }

    setCurrentCell(0, 0);
}
bool Spreadsheet::readFile(const QString &fileName)
{
    QFile file(fileName);
    if (!file.open(QIODevice::ReadOnly))
    {
        QMessageBox::warning(this, tr("Spreadsheet"), tr("Cannot read file %1:\n%2.").arg(file.fileName()).arg(file.errorString()));

        return false;
    }

    QDataStream in(&file);
    in.setVersion(QDataStream::Qt_4_3);

    quint32 magic;
    in>>magic;
    if (magic != MagicNumber)
    {
        QMessageBox::warning(this, tr("Spreadsheet"), tr("The file is not a Spreadsheet file."));

        return false;
    }
    clear();

    quint16 row;
    quint16 column;
    QString str;

    QApplication::setOverrideCursor(Qt::WaitCursor);
    while (!in.atEnd()) {
        in >> row >> column >> str;
        setFormula(row, column, str);
    }
    QApplication::restoreOverrideCursor();

    return true;
}
bool Spreadsheet::writeFile(const QString &fileName)
{
    QFile file(fileName);

    if (!file.open(QIODevice::WriteOnly))
    {
        QMessageBox::warning(this, tr("Spreadsheet"), tr("Connot write file %1:\n%2").arg(file.fileName()).arg(file.errorString()));

        return false;
    }
    //将文件的数据以数据流形式输出
    QDataStream out(&file);
    out.setVersion(QDataStream::Qt_4_3);

    out << quint32(MagicNumber);

    //设置光标状态
    QApplication::setOverrideCursor(Qt::WaitCursor);
    for (int row=0; row<RowCount; ++row)
    {
        for (int column=0; column<ColumnCount; ++column)
        {
            QString str = formula(row, column);
            if (!str.isEmpty())
                out << quint16(row) << quint16(column) << str;
        }
    }
    QApplication::restoreOverrideCursor();

    return true;
}
void Spreadsheet::somethingChanged()
{
    if (autoRecalc)
        recalculate();
    emit modified();
}
Cell *Spreadsheet::cell(int row, int column) const
{
    return static_cast<Cell *>(item(row, column));
}
QString Spreadsheet::text(int row, int column) const
{
    Cell *c = cell(row, column);
    if (c) {
        return c->text();
    } else {
        return "";
    }
}
void Spreadsheet::setFormula(int row, int column, const QString &formula)
{
    Cell *c = cell(row, column);
    if (!c)
    {
        c = new Cell;
        setItem(row, column, c);
    }
    c->setFormula(formula);
}

QString Spreadsheet::formula(int row, int column) const
{
    Cell *c = cell(row, column);
    if (c)
    {
        return c->formula();
    }else{
        return "";
    }
}

